Buoyant coring apparatus



March 25, 1959 A. M. ROSFELDER BUOYANT GORINGi APPARATUS Sheet FiledJune 26, 1967 FIG.

FIG. 2.

March 25, 1969 A. M. ROSFELDER 3,434,551

BUOYANT comm APPARATUS Filed June 26, 1967 Sheet 2 of 2 g INVENTOR.

ANDRE M. ROSFELDER ATTORNEY.

US. Cl. 175-6 1t] Claims ABSTRACT OF THE DISCLOSURE The descriptiondiscloses a buoyant rig for supporting coring operations of anunderwater coring barrel. The buoyant rig includes a fioat and a bottomweighted stand which are interconnected by at least one guide wire. Thecore barrel slidably extends through the weighted stand and ispositioned parallel to the guide wire and is slidable therealong by aguide means. When the core barrel is powered the barrel will be guidedalong the guide wire as it penetrates the ocean bottom. A gimbalconnection between the core barrel and the stand for uneven oceanbottoms and the guide wire may be separated from the stand after asample is obtained so that the float will raise the core barrel and theremaining rigging apparatus to the ocean surface.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

In deep sea coring operations it is highly impractical to attemptdrilling from a surface ship because of the weight of the long drivingelements which would be required between the ship and the coring barrel.One of the easiest methods of obtaining a deep sea core sample is toutilize a free corer such as that illustrated in the patent to Charltonet al., US. Patent No. 3,295,616, or that illustrated in a patent toMoore, US. Patent No. 3,078,931. While such free fall coring devices aresimple to operate, the length of core sample obtainable therefrom islimited since the driving force for a such a corer is entirely dependentupon the submerged weight of the device.

In order to obtain long core samples from a deep sea environment it isnecessary that the coring barrel be powered by a submerged power meansand that some sort of rigging be set up on the ocean floor to supportthe core barrel during the driving operation. Conventional rigging hastaken the form of tripods, quadripods, or other kinds of rigid frames.This type of rigging has been very difiicult to handle aboard anoceanographic vessel and also it is very difiicult to set up firmly onan uneven ocean bottom. In view of the increasing demand for deep seacore samples, there now exists an urgent need for a simpler riggingapparatus which can be easily handled.

The present invention provides a rigging apparatus which is notperplexed with the problems of material handling and set up on the oceanbottom. This has been accomplished essentially by a float and a bottomweight stand which are interconnected by one or two guide wires. Thecore barrel slidably extends through the weight stand and uponpenetration into the ocean bottom the guide wire acts as a rail inguiding the downward movement. Such an arrangement avoids thecomplexities of conventional rigid framed rigs and is much simpler tohandle from an oceanographic vessel. Of considerable importance is theease with which such an arrangement can be set up on the ocean bottom.The weight stand provides the lowest possible center of gravity of theoverall apparatus and will quickly assume a steadfast position on theocean bottom. 70

On uneven bottoms the present invention may be easily adapted to obtainvertical core samples. This may be ac- 3,434,551 Patented Mar. 25, 1969complished by a gimbal connection between the coring barrel and theweighted stand. The coring operation may also be facilitated by a pistonwhich is slidably disposed Within the coring barrel and is attached by awire to the float. This piston will cause a suction which facilitatesentry of the bottom sediment into the coring barrel. The presentinvention also lends itself to a quick and easy retrieval of the coringbarrel after a bottom sample has been obtained. This may be accomplishedby a means for separating the guide wire from the weight stand whereuponthe float will withdraw the coring barrel from the ocean bottom andraise the apparatus less the weight stand to the ocean surface.

An object of the present invention is to overcome all of theaforementioned problems of the prior art.

Another object is to provide a submerged power driven coring barrel anda simple and easy to use rigging apparatus for positioning the coringbarrel on the ocean bottom.

A further object is to provide an underwater powered coring barrel andbottom rigging apparatus therefor which, after the core sample has beenobtained, can be raised to the ocean surface without using at raisingcable.

Still another object is to provide an underwater powered coring barreland a bottom rigging apparatus which, upon coming to rest upon an unevenbottom, will vertically position and guide the coring barrel during itspenetration of the ocean bottom.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic side view, partly in cross section, showing acoring barrel positioned by a rigging apparatus on the ocean bottom;

FIG. 2 is an enlarged detail illustration of the connection of thecoring barrel to the weighted stand;

FIG. 3 is a schematic side illustration, partly in cross section,showing another embodiment of my invention wherein a coring barrel issupported on the ocean bottom by a buoyant rigging apparatus; and

FIG. 4 is a schematic side view, partly in cross section, illustratingstill another embodiment of my invention.

Referring now to the drawings wherein like reference numerals designatelike or similar parts throughout the several views, there is shown inFIG. 1 a coring barrel 10 which is supported in a coring position on theocean floor by a buoyant rigging apparatus which is generally designatedat 12. The rigging apparatus 12 includes a weighted bottom stand 14 anda float 16 which are interconnected by a guide wire 18. The guide wire18 may be connected directly to the weighted stand 14 or as shown may beconnected to other elements which are in turn connected to the weightedstand. Because of the action of the float 16 the guide wire 18 willassume a vertical positoin which is desirable for coring operations tobe described hereinafter.

The coring barrel 10 slidably extends through the weighted stand 14 andas shown this may be accomplished by a support sleeve 20 which slidablyreceives the coring barrel and is connected by suitable means to theweighted stand 14. For flat bottom coring the support sleeve 20 may berigidly connected in an upright position to the Weighted stand 14,however on an uneven bottom such an arrangement will result in anon-vertical core. To obtain vertical core samples from an uneven oceanbottom I have found it desirable to connect the support sleeve 20 to theweighted stand 14 by a gimbal arrangement 22 (see FIG. 2). The supportsleeve 20 and the weighted stand 14 may form inner and outer ringsrespectively of the gimbals with a middle ring alternately pinnedthereto at intervals. Accordingly, when the weighted stand is brought torest on the ocean bottom the coring barrel l0 will have freedom ofmovement in any direction thereabove.

It is highly desirable during coring operations to obtain a verticalcore sample since all coring data is documented and correlated on avertical depth basis. The obtaining of a vertical core sample from aninclined ocean bottom is quite difiicult with conventional corers. Ihave enabled vertical core sampling by utilizing the vertical extensionof the guide wire 18. This may be accomplished by a means which slidablyinterconnects the core barrel to the guide wire 18 for positioning thebarrel substantially parallel to the guide wire and guiding penetrationof the barrel along the vertical extension of the wire. This positioningand guidance may be simply a guide tube 24 which receives the guide wire18 and may be rigidly connected to the side of the core barrel 10 by anysuitable means such as welding.

The particular coring barrel 10 shown in FIG. 1 is powered by avibrohammer 26 which may be rigidly connected at the top of the coringbarrel 10, the coring barrel 10 having a port 28 immediately below thevibrohammer for discharging water in the coring barrel upon penetration.The vibrohammer 26 may be hydraulically operated by a pump (not shown)mounted on the weighted stand 14, or alternatively may be electricallypowered by an electric cable 30 which extends from a surface ship (notshown), The electric cable 30 extends first to a ring 32 which isslidable along the guide wire 18, thence to the bottom of the float 16,and then to a spring actuated reel 34 which may be mounted at the top ofthe vibrohammer 26. From the reel the electric cable 30 is electricallyconnected to the vibrohammer and is unreeled as the coring barrel 10penetrates the ocean bottom.

In order to facilitate penetration of the coring barrel 10 into theocean bottom I have found it desirable to slidably mount a piston 36within the coring barrel 10 and connect the piston to the float 16 by awire 38 which extends longitudinally along the interior of the coringbarrel 10. Accordingly, when the coring barrel is operated to penetratethe ocean bottom the piston 36 will remain stationary on the oceanbottom and provide a suction force within the coring barrel immediatelyabove the core sample. Upon withdrawal of the coring barrel 10 from theocean bottom there will be a tendency for the piston 36 to be drawndownwardly within the coring barrel because of suction in the coringhole immediately below the coring head of the barrel. This action wouldresult in a loss of the core sample and is highly undesirable. Loss ofthe core sample may be prevented by a locking means 40 which isconnected at the top of the coring barrel 10 and receives the wire 38for locking the piston wire to prevent downward movement of the piston36 within the coring barrel. The locking means 40 may be actuated by thevibrohammer 26 and unlocked. During raising and lowering of the rig theclamp means 40 will lock the wire 38 in place since during these periodsthe vibrohammer is inoperative.

In the embodiment shown in FIG. 1 the float 16 is utilized for thepurpose of raising the coring barrel 10 to the surface of the waterafter a sample has been obtained. This has been accomplished byseparating the guide wire 18 from the weighted stand 14 and making thefloat 16 sufliciently buoyant to withdraw the coring barrel 10 from theocean bottom and lift the coring barrel, its sample, and the riggingexcept for the weighted stand 14 to the surface of the water. The guidewire 18 may be separated from the weighted stand 14 by an annularexplosive bolt (not shown) which is disposed within the slidable ring32. The explosive bolt will be actuated by an initiator (not shown)which is connected to and is actuated by a small electric wire (notshown) which extends along the cable 30. In order to perform the raisingoperation after separation of the guide wire 18, the clamp means 40locks the piston wire 38. As a supplementary raising means, a raisinghead 42 may be rigidly connected at a desired location on the guide wire18 above the sliding ring 32. This raising head 42 serves as a stop forthe downward penetration of the coring barrel 10 when the head 42 comesinto engagement with the bottom of the guide tube 24. When corepenetration has ceased due to this stopping action, the electrical loadon the vibrohammer 26 will be lessened which can be detected at thesurface ship as an indication that the coring barrel has penetrated theocean bottom to a desired depth. Upon such an indication the explosivebolt within the ring 32 can be actuated to cut the guide wire below theraising head 42. The raising head 42 may be adjustable along the guidewire 18 so as to select the desired depth of penetration of the coringbarrel 10.

The float 16 may be simply a hollow spherical glass float. The weightedstand 14 may be constructed of any suitable heavy material such asconcrete and should be heavy enough to provide a negative buoyancy forthe entire apparatus when it is connected thereto. The weighted stand 14preferably has a large lateral bottom area so as to ensure secureemplacement on the ocean bottom.

In the operation of the FIG. 1 embodiment the coring barrel 10 and therigging apparatus 12 are placed in the water from a surface ship. Theweighted stand 14 causes the entire assembly to descend in an uprightposition and come to rest on the ocean bottom. If the ocean bottom isuneven and the weighted stand 14 assumes a slanted position, as shown inFIG. 1, the float 16, by action of the guide wire 18, pivots the coringbarrel 10 within the gimbals 22 to cause the coring barrel to assume anupright position. The surface ship then feeds electrical power to thevibrohammer 26 which causes the coring barrel 10 to penetrate the oceanbottom. The coring barrel 10 is guided in a downward vertical directionby action of the guide tube 24 about the guide wire 18. When the bottomof the guide wire 24 engages the top of the raising head 42 penetrationceases which will lessen the electrical load on the vibrohammer 26. Whenthis change in electrical load is detected at the surface ship theexplosive bolt charge within the sliding ring 32 is actuated to cut theguide wire 18 below the raising head 42. This then releases the float 16and the coring barrel 10 from the weighted stand 14. The upward force ofthe float 16 is applied to the coring barrel through the locked clampmeans 40 and/ or to the bottom of the guide tube 24 by the raising head42 to cause Withdrawal of the coring barrel 10 from the coring hole andthe support sleeve 20 and raise the entire assembly less the weightedstand to the surface of the water. The assembly will then float on thesurface of the water until retrieved by the surface ship.

In FIG. 3 there is shown another embodiment of the invention which issimilar to the FIG. 1 embodiment except that the FIG. 3 embodimentshowsthe use of a hydraulic jet type coring barrel 44 which is not gimbalmounted in a weighted stand 46. The jetting action of the coring barrel44 is enabled by a short tube 48 which is mounted about the coringbarrel just above the cutting head. The short tube 48 is sealed at itstop and bottom to the coring barrel with the exception of a series ofsmall ports 50 at its bottom end and a rigid hydraulic duct 52 whichopens into the top of the tube 48 and extends longitudinally upwardalong the side of the coring barrel. A hydraulic pump 54 is connected tothe top of the duct 52 by a hose 56 for interjecting water through theports 50. The jetting action of the water through the ports 50 cuts thebottom sediment to allow downward penetration of the coring barrel 44.The pump 54 may be electrically powered by a cable 58 from the surfaceship.

The coring barrel 44 may extend slidably through the weighted stand 46by a support sleeve 60. The exterior of the sleeve 60 may be rigidlyfixed to the weighted stand and the coring barrel 44 will be slidabletherethrough. The support sleeve 60 will be provided with an annulardepression (not shown) for slidably receiving the duct 52 along the sideof the coring barrel.

A slip ring 62 (not containing an explosive bolt) is used for raisingand lowering the whole assembly by engagement with the bottom of guidetube 24. The clamp means 40 is a one way lock of the piston wire 38allowing the piston 36 to only slide in an up direction within thecoring barrel 44. This clamp means may simply comprise a pair ofeccentric clamps.

Still another embodiment of the present invention is shown in FIG. 4.The FIG. 4 embodiment differs from the previously described embodimentsin that two guide wires 18 are used for interconnecting the float 16 tothe weighted stand 14. A coring barrel 64 is slidably mounted throughthe weighted stand 14 by the support sleeve 20 and gimbal means 22. Thecoring barrel 64 is disposed between the guide wires 18 and at its topit is provided with a rotary head 66 for rotatably driving the coringbarrel 64 into the ocean bottom. Upon such driving action ports 68within the top of the coring barrel 64 discharge water trapped therein.

A pair of guide tubes 24, each receiving a respective guide wire 18, aremounted at opposite sides to the rotary head 66. The rotary head 66 maybe operated hydraulically by a pump 54 which is connected to the head bya hose 56. If expendable, the pump 54 may be mounted on the stand 14 andif not it may be mounted on top of the rotary head 66. The hose 56 isprovided with a quick pull disconnect 70 and may be fed into the top ofthe head by a pulley 72 mounted at the bottom of the float 16.

Since operation of the rotary head 66 will tend to apply a twistingaction to the guide wires 18, oppositely directed ports 74 may beprovided within the head for providing a jetting action to counteractthe torque of the rotary head.

In a manner similar to the FIG. 1 embodiment, each of the guide wires 18of the FIG. 4 embodiment is provided with a respective lifting head 42and an explosive bolt ring 32 for cutting the guide wire 18 therebelow.

The operation of the FIG. 4 embodiment is similar to the FIG. 1embodiment. When the bottom of the guide tubes 24 come to rest on thelifting heads 42 the load on the rotary head 66 is lessened and thisindication tells surface personnel to actuate the explosive rings 32.The explosive rings 32 cut the guide wires 18 and the float 16 lifts thewhole assembly with the exception of the weighted stand 14 and the pump54 to the water surface. The hose 56 will be disconnected by the quickdisconnect 70.

It is now readily apparent that the present invention provides a deepsea coring apparatus which is considerably more efficient to handle thanconventional corers.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:

1. In combination with an underwater powered core barrel, a buoyant rigcomprising:

a weighted bottom stand adapted to rest on the ocean bottom, said corebarrel extending slidably therethrough;

at least one guide wire connecting the float to the stand so that thefloat will extend the wire substantially vertically upright from thestand; and

means slidably interconnecting the core barrel to the guide wire forpositioning the barrel substantially parallel to the guide wire andguiding penetration of the barrel along the vertical extension of thewire.

2. The combination as claimed in claim 1 including:

means for separating the guide wire from said stand.

3. The combination as claimed in claim 2 wherein:

said float is sufliciently buoyant to lift the rig and barrel with asample after separation of the guide.

wire.

4. The combination as claimed in claim 1 wherein:

gimbal means slidably interconnects the core barrel to said stand.

5. A combination as claimed in claim 1 including:

a second guide wire connecting the float to the stand so that the floatwill extend the second wire substantially vertically upright from thestand;

a second means slidably interconnecting the core barrel to the secondguide wire and cooperating with the first mentioned positioning meansfor positioning the barrel substantially parallel to the guide wires andguiding penetration of the barrel along the vertical extension of thewires.

6. A combination as claimed in claim 1 including:

a piston slidably mounted within the core barrel and adapted to remainstationary on the ocean bottom and provide a suction within said barrelas the barrel penetrates the ocean bottom;

a second wire, the second wire extending along the interior of thebarrel and interconnecting the float and said piston; and

one way locking means connected to the core barrel for locking thepiston wire to prevent downward movement of the piston within the corebarrel.

7. A combination as claimed in claim 6 wherein:

gimbal means slidably interconnects the core barrel to said stand.

8. A combination as claimed in claim 7 including:

means for separating the guide wire from said stand.

9. A combination as claimed in claim 8 wherein:

said float is sufliciently buoyant to lift the rig and barrel with asample after separation of the guide wire.

10. A combination as claimed in claim 9 including:

a lowering cable; and

means slidably connecting the lowering cable to the guide wire.

References Cited UNITED STATES PATENTS 3,279,547 10/1966 Berne et a1.1756 3,372,760 3/ 1968 Raymond et al. 175-5 3,373,827 3/ 1968 Biron etal. 175-6 ERNEST R. PURSER, Primary Examiner.

U.S. Cl. X.R. 245, 248

